Extraction of microalgae derived lipids with supercritical carbon dioxide in an industrial relevant pilot plant

Abstract

Microalgae are capable of producing up to 70% w/w triglycerides with respect to their dry cell weight. Since microalgae utilize the greenhouse gas CO2, they can be cultivated on marginal lands and grow up to ten times faster than terrestrial plants, the generation of algae oils is a promising option for the development of sustainable bioprocesses, that are of interest for the chemical lubricant, cosmetic and food industry. For the first time we have carried out the optimization of supercritical carbon dioxide (SCCO2) mediated lipid extraction from biomass of the microalgae Scenedesmus obliquus and Scenedesmus obtusiusculus under industrrially relevant conditions. All experiments were carried out in an industrial pilot plant setting, according to current ATEX directives, with batch sizes up to 1.3 kg. Different combinations of pressure (7–80 MPa), temperature (20–200 °C) and CO2 to biomass ratio (20–200) have been tested on the dried biomass. The most efficient conditions were found to be 12 MPa pressure, a temperature of 20 °C and a CO2 to biomass ratio of 100, resulting in a high extraction efficiency of up to 92%. Since the optimized CO2 extraction still yields a crude triglyceride product that contains various algae derived contaminants, such as chlorophyll and carotenoids, a very effective and scalable purification procedure, based on cost efficient bentonite based adsorbers, was devised. In addition to the sequential extraction and purification procedure, we present a consolidated online-bleaching procedure for algae derived oils that is realized within the supercritical CO2 extraction plant.

Production of chemicals from microalgae lipids – status and perspectives

“…In a next step, the products are extracted with an organic solvent. As an alternative, extraction with supercritical CO 2 is also developed [221][222][223][224][225]. Supercritical CO 2 extraction has several advantages: The extraction efficiency is high since the fluid density and consequently the solvent quality can be controlled by changes of pressure or temperature, it allows for low-temperature processing, is non-toxic, nonflammable, and the supercritical solvent can easily be removed [224,226,227].…”

Supercritical carbon dioxide extraction and fractionation of lipids from freeze-dried microalgae Nannochloropsis oculata and Chlorella vulgaris

“…Supercritical carbon dioxide (ScCO 2 ) extraction of microalgal lipids has received attention as an alternative to organic solvent extraction and has been shown to be an ideal method for extracting certain lipids [7]. Several studies reported high extraction yield using ScCO 2 [8] [9] [10]. However, from these works, it appears that the microalgae Abbreviations: SPE, solid phase extraction; PPL, phospholipids; GL, glycolipids; NL, neutral lipids; ScCO 2 , supercritical carbon dioxide ⁎ Corresponding author at: Laboratoire de Chimie Agro-industrielle (LCA), Université pretreatment is highly significant to perform an efficient extraction with ScC0 2 .…”

Establishment of the Volatile Signature of Wine-Based Aromatic Vinegars Subjected to Maceration

“…Venturi et al [ 9 ] developed a phenol-enriched refined olive oil with its own phenolic compounds extracted from wastewater produced during physical processing in order to improve the nutraceutical value, as well as the antioxidant capacity of olive oil. On the other hand, marine sources (e.g., macroalgae, microalgae), food by-products and plant-derived natural products can be used to extract bioactive compounds, such as polyunsaturated fatty acids (PUFAs) and phenolics, among others, that are widely recognized as important nutritional components that may help prevent various cardiac disorders [ 10 , 11 , 12 , 13 ].…”